When I try to send an e-mail to a single person or a group of persons form my contact list, I get error code -50 (e-mail is not sent as result of not converted e-mailreceptant = rough translation). 
When I double click on the name of the person, the e-mail adress appairs, but still it is not sending. Even when I try to manually type in the e-mailadress, it automatically takes the contact person from my Contact Persons list (which is aparantly not converted in the right way). 

Who can help me to solve this? 

Thanks in advance, Wendy

I have added a contact person in my address book yesterday but I went back in there today to try and put there email address in but there is not a place for it to go and if so where is it, cause I can't find it?

When creating a message and pressing, for example "A" as the first l;etter of the contact person, up until 4 days ago, every contact I have which begins with that letter would pop up. Now, no names appear. What can I do to restore former response?